Which equation correctly relates mechanical energy, thermal energy, and total energy when there is friction present in a system?
2 answers:
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Answer:
The minimum force the climber must exert is about 439N.
Explanation:
We use the relationship between friction and normal force to answer this question:
We are given the static coefficients of friction but need to determine the friction force. To do that we consider the totality of forces acting on this hapless gentleman stuck in a chimney. There is the gravity acting downward (+), then there are two friction forces acting upward (-), namely through his shoes and his back. The horizontal force exerted by the climber on both walls of the chimney is the same and is met with equally opposing normal force. Since the climber is not falling the net force in the vertical direction is zero:
The normal force in this equilibrium is about 439N and because we are told that the static friction forces are both at their maximum, this value is at the same time the <em>minimum</em> force needed for the climber to avoid starting slipping down the chimney.
We are given volume of gasoline = 15.58 L and
Density = 0.74 g/mL.
Density is given in grams(g) per milliliter (mL). So, we need to convert given volume in mL also.
We know, 1 litre = 1000 milliliters
Therefore, 15.58 L = 15.58 * 1000 mL = 15580 mL
We could rewrite,
Volume of gasoline = 15580 mL.
Formula for density is..
Density (ρ)=
Plugging values in formula,
0.74 g/mL =
Muliplying both sides by 15580.
11529.2g = mass.
Therefore, 11529.2g grams does 15.58 L of gasoline weigh.
Answer:
c) 10.7m/s
Explanation:
From the exercise we know that at 5m the ball is traveling at 4m/s
To calculate its initial velocity we need to solve the following equation:
Since the initial height is 0
Solving for